PURPOSE: To provide a folding fan by which wind force becomes large even by slight fanning and which can be diverted even to a simple hat.

CONSTITUTION: A folding fan is provided with plural long size parts 12 which have first and second bending parts 12a and 12b having an almost similar shape and are superposed in a layer shape, a pivot part 14 to which one ends of the long size parts are joined through a fastener so that the long size parts can freely rotate and a fan screen part 15 which is unfolded on the obverse side of the plural long size parts 12 and can be folded up according to rotation of the long size parts, and the fan screen part 15 is expanded, and can be used as a fan, and a fanwise mesh member arranged on the reverse side of the fan screen part 15 is expanded, and can be used as a hat according to its necessity.